2020年第67回応用物理学会春季学術講演会

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合同セッションK「ワイドギャップ酸化物半導体材料・デバイス」 » 21.1 合同セッションK 「ワイドギャップ酸化物半導体材料・デバイス」

[12p-D419-1~15] 21.1 合同セッションK 「ワイドギャップ酸化物半導体材料・デバイス」

2020年3月12日(木) 13:45 〜 17:45 D419 (11-419)

大島 孝仁(FLOSFIA)、東脇 正高(情通機構)

16:00 〜 16:15

[12p-D419-9] The role of water in the synthesis of AlOx thin films by a mist chemical vapor deposition

〇(DC)Arifuzzaman Rajib Rajib1、Abdul Kuddus1、Karim Enamul1、Shunji Kurosu2、Tomofumi Ukai2、Yasuhiko Fujii2、Masahide Tokuda2、Tatsuro Hanajiri2、Ryo Ishikawa1、Keiji Ueno1、Hajime Shirai1 (1.Saitama Univ.、2.Toyo Univ.)

キーワード:mist-CVD, Alumina, Water addition

The role of water as an additive during the synthesis of aluminum oxide (AlOx) thin films by mist chemical vapor deposition (mist CVD) was investigated. This study was based on deposition using aluminum acetylacetonate (Al(acac)3) and methanol (MeOH), while also exposing some films to water or methanol mists after fabrication. Analysis by AFM and FTIR spectroscopy established that the AlOx films fabricated from Al(acac)3 using methanol as the sole exhibited a distorted Al(OH) network, including a high concentration of OH groups. The addition of water to the Al(acac)3/MeOH precursor decreased the film deposition rate and also lead to marked reductions in both the surface roughness and -OH concentration. Exposing the Al(OH) films to water mist after synthesis resulted in etching together with the removal of -OH groups and decreases in surface roughness. Exposure to water induced no significant changes in the surface chemistry or morphology of AlOx thin films deposited at a MeOH:water volume ratio of 7:3. However, FTIR spectra demonstrated that exposing these AlOx films to a MeOH mist promoted the formation of Al(OH) bonds. Figure 1 shows the schematic of the growth surface for the MeOH:water ratios of 10:0 and 7:3. The results of this work indicate that the incorporation of -OH groups into the AlOx network generates both network distortion and inhomogeneity. It is also evident that water present during film growth removes -OH groups during the growth, resulting in the formation of a dense, uniform AlOx network. The effect of the substrate bias on the AlOx film properties will be also presented.